1. Field of the Invention
This invention relates to a method for preventing cut pieces of agricultural products containing starch, particularly those of potatoes, from sticking to each other in the drying and cooking steps.
2. Description of the Related Art Including Information Disclosed Under 37CFR 1.97-1.99
When cut pieces of agricultural products containing much starch, particularly those of poptatoes, are treated in various ways, such as heating, drying and cooking, the starch existing on the surfaces of said cut pieces tends to gelatinize to increase the viscosity of the water clinging to the surfaces. thus causing sticking of the cut pieces to each other and forming massive particles. It was therefore impossible to treat a large quantity of cut pieces at a time. Accordingly, it was necessary to supply cut pieces sparsely lined up to a dryer, as disclosed in U.S. Pat. No. 4,906,483, or to sparsely arrange cut pieces on a conveyer to a dryer, as disclosed in U.S. Pat. No. 4,800,090. These methods are suitable for treating a small quantity of cut pieces. but are not suitable undoubtedly when a large quantity of cut pieces is treated. In addition, it has also been attempted, as disclosed in Japanese Patent Kokai No. 109764/1984, to float cut pieces, while being passed through a heater and a dryer by means of a conveyer, by flowing a heat transfer medium, such as hot air and superheated steam, in large quantities, thereby preventing the cut pieces from sticking to each other. This method requires not only the use of a large-sized dryer but also a large quantity of energy to supply a sufficient air flow for floating the cut pieces, thereby markedly lowering the energy efficiency in the drying and cooking operations.
As described above, in order to prevent cut pieces of agricultural products containing much starch, particularly those of potatoes, from sticking to each other, were proposed a method of treating a small quantity of sparsely arranged cut pieces, a method of treating a large quantity of cut pieces sparsely dispersed in large-sized equipment and a method of treating cut pieces floated by a powerful air blast. However, these methods involve many problems in terms of plant investment and running cost, and no effective method has yet been developed. Frying of these cut pieces, on the other hand, rarely suffers from such problems because sticking of cut pieces to each other does not take place.
In recent years, the demand for low-calory and low-fat foodstuffs has been increasing because of the enhanced concern of general consumers for health. Attempts have been repeated for the industrial production of dried and crispened foodstuffs without frying in place of the conventional fried foodstuffs of a high calorific value containing much fat exemplified by potato chips, but no effective method has yet been developed. Thus, establishing a low-cost, industrial method for producing foodstuffs from potatoes and other agricultural products containing much starch by drying and crispening without frying will respond to the concern of consumers for health.